The Groningen Social Assistance Benefits Experiment
Last registered on December 06, 2018


Trial Information
General Information
The Groningen Social Assistance Benefits Experiment
Initial registration date
December 04, 2018
Last updated
December 06, 2018 8:26 AM EST

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Primary Investigator
University of Groningen
Other Primary Investigator(s)
PI Affiliation
Municipality of Groningen
PI Affiliation
University of Groningen
PI Affiliation
University of Groningen
Additional Trial Information
On going
Start date
End date
Secondary IDs
In the Netherlands dissatisfaction with the current scheme of social welfare has led various Dutch cities to run field experiments to test out new ways of delivering income support to its citizens. Among them is the City of Groningen where the study goes by the name ‘Bijstand op Maat’ (English: Tailored Social Assistance) and includes around 900 current recipients of public income support (also social assistance or minimum income guarantee). For the duration of the trial job search requirements and welfare sanctions tied to income support will be eliminated to make room for more autonomy (treatment 1). Other aspects include a more tailor-made approach in supporting welfare recipients (treatment 2) and increasing financial incentives to take up paid work (treatment 3). As a specific treatment (4) a randomized selected group may actually choose between the first three treatments the investigate the effect of self-selection on the outcomes. The study is set up as a randomized controlled trial (RCT) with interventions running from November 2017 to September 2019. Outcomes of interest are differences in the uptake of paid work (full time and part time), societal participation and social activation, participants’ health and well-being, participants’ satisfaction with the new scheme, as well as their financial situation.
External Link(s)
Registration Citation
Edzes, Arjen et al. 2018. "The Groningen Social Assistance Benefits Experiment ." AEA RCT Registry. December 06.
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Experimental Details
This study includes four treatment conditions, one control condition and a reference group. In the control condition, claimants are subject to the rules and regulation of the Dutch status quo social welfare regime. It is instructive to briefly introduce the status quo regime. Social welfare in the Netherlands is a non-contributory transfer programme that provides monthly income support to poor households identified based on a means, and work test. The regulations are extensive and complex, which is why we focus on the most important rules and regulations. The regime foresees a monthly transfer payment of maximum 992 EUR for a single-person household. On top of that welfare claimants may be eligible for child, housing and healthcare allowances. The policy is designed as a temporary safety net aiming to deliver income support until recipients can provide for their own income again (mostly by finding employment). Accordingly, welfare recipients have to comply with certain rules, such as writing application letters, accepting job offers or following skill-development programmes. Recipients that fail to comply with the rules may be sanctioned by freezing or cutting their monthly payment. Exemptions apply to those who are incapacitated for work or face severe health problems. Local governments (municipalities and regional councils) are charged with the task of executing the scheme.

In the four treatment conditions the rules and regulations are varied. The four interventions tested are: (1) claimants are exempted from the usual obligations to maintain their benefit, such as applying for jobs or joining reintegration programmes; (2) claimants receive extra support through tailor-made supervision and intensive mediation from the welfare agency (=Municipality of Groningen; (3) claimants are allowed to keep additionally earned income to a larger extent than under current regulations (current: keep 25% of additionally earned income up to max. 199 EUR/month for max. six months; intervention: keep 50% of additionally earned income up to max. 202 EUR/month for max. 16 months); (4) claimants may choose between one of the first three treatments to investigate the effect of self-selection. Additionally, we use administrative data to follow a reference group of randomly selected claimants who were not invited to participate in the trial.
Intervention Start Date
Intervention End Date
Primary Outcomes
Primary Outcomes (end points)
Our primary outcome indicator concerns differences in the uptake of paid work (full time and part time).
Primary Outcomes (explanation)
The uptake of paid work will be measured using administrative micro-data from Statistics Netherlands.
Secondary Outcomes
Secondary Outcomes (end points)
Our secondary outcome indicators are (1) societal participation and social activation, (2) participants’ health and well-being, (3) participants’ satisfaction with the scheme, and (4) recipients’ financial situation.
Secondary Outcomes (explanation)
Societal participation and social activation is measured through self-reported survey data (e.g. hours of volunteer work). Participants’ health and well-being is measured using medical data from Statistics Netherlands (e.g. drug use) and self-reported survey data (e.g. Mental Health Inventory 5). Participants’ satisfaction with the scheme is measured through self-reported survey data. Participants’ financial situation is measured using administrative data and self-reported survey data.
Experimental Design
Experimental Design
The experiment is a cooperation between the University of Groningen and the Municipality of Groningen. Participating welfare claimants are randomly assigned to the five different conditions described above (four treatments groups and one control group). The target population for the experiment consists of all welfare claimants in Groningen, unless participating is a risk or not possible. After selection of 150 claimants for the reference group, the rest of the target population is randomized over the five groups (four treatments groups and one control group). After this randomized distribution Claimants were invited to participate for that specific treatment during a large-scale information and enrollment campaign. Participation had to be confirmed by signing an informed consent sheet. Participation is voluntary, which means that participants can decide to drop out at any time. In total, 891 claimants have signed up to take part in the study, which makes up for around 10% of the targeted population. Data is collected using administrative data as well as surveys. Data collection takes place at three points of time: Okt – Nov 2017 (baseline), Okt - Nov 2018 (midline) and Aug – Sep 2019 (endline).
Experimental Design Details
Not available
Randomization Method
After selection of the target group the randomization is done in office by a computer
Randomization Unit
Was the treatment clustered?
Experiment Characteristics
Sample size: planned number of clusters
Sample size: planned number of observations
Sample size (or number of clusters) by treatment arms
Treatment 1: 183 claimants; Treatment 2: 144 claimants; Treatment 3: 153 claimants; Treatment 4: (1) 73, (2) 58, (3), 58; Control: 222 claimants.
Minimum detectable effect size for main outcomes (accounting for sample design and clustering)
The goal was to assign at least 150 individuals to each group. The minimum sample size was chosen based on a power test
IRB Name
IRB Approval Date
IRB Approval Number